Most of the obvious anatomical homologies are between anatomical structures which are in active use by the species in question, but some anatomical homologies involve structures which are no longer needed but which also haven't disappeared entirely. A vestigial organ or structure is any organ or structure found in a species which is not being used as it is in other species. Contrary to popular belief, vestigial organs and vestigial structures aren't necessarily useless or functionless.

Vestigial does not mean useless or nonfunctional because it is difficult if not impossible to prove that any particular structure is actually functionless. It is possible that some vestigial organ really is functionless, but scientists and biologists don't assume so dogmatically. All that's necessary for an organ or structure to be labeled "vestigial" is for there to be homologies in other species where the use or function is clear, but that same use or function is not the case for the species in question. The use may be odd or it may simply not be identified yet.

A Whale of a Pelvic Bone

An example of such a structure is the pelvis of whales. All tetrapods (including whales) have pelvic bones. In most animals the pelvic bones are needed in order to be able to move the lower or rear set of limbs for the purpose of locomotion. In some species, such as whales, these limbs don't exist for the most part — although vestiges of them may remain.

Despite this lack of any need for them, whales still have pelvic bones. They are quite small compared to their counterparts in other animals, but they exist. Perhaps they serve some function such as helping to support the whales reproductive anatomy, but there are many different types of structures which would be better suited to such a task.

The question is, why would a whale, which basically lacks lower limbs and doesn't need pelvic bones to move, have pelvic bones that are homologous to creatures that do need pelvic bones to move? Similar homologies exist for snakes and legless lizards. Once again, the only explanation that makes sense is if these creatures evolved from a common ancestor along with all the other tetrapods.

I find that thereÃ¢â‚¬â„¢s a lot of contradiction when creationists address the issue of vestiges. You start talking about evolution, and theyÃ¢â‚¬â„¢ll say things like Ã¢â‚¬Å“ThereÃ¢â‚¬â„¢s no advantage to having a partially formed [insert trait here]. It would be useless.Ã¢â‚¬Â

Then you switch the topic to vestiges, and suddenly partially formed tails, pelvic bones, fingers, wings, ect. have all kinds of useful purposes that the animals couldnÃ¢â‚¬â„¢t like without.

I find that thereÃ¢â‚¬â„¢s a lot of contradiction when creationists address the issue of vestiges. You start talking about evolution, and theyÃ¢â‚¬â„¢ll say things like Ã¢â‚¬Å“ThereÃ¢â‚¬â„¢s no advantage to having a partially formed [insert trait here]. It would be useless.Ã¢â‚¬Â

Then you switch the topic to vestiges, and suddenly partially formed tails, pelvic bones, fingers, wings, ect. have all kinds of useful purposes that the animals couldnÃ¢â‚¬â„¢t like without.

I've heard contradictions from evos also. First, there is the implication that vestigial organs are useless leftovers of evolution, but yet when natural selection is brought up and the why of it still being there, well there are still purposes for the organs.

We now know the appendix is useful in that it fights harmful bacteria in our intestines. Now it will surely be spun that "see, it is still there because it was selected for." This only shows macro evolution is in your head. How do you know it wasn't created that way?

Just like whale legs. Funny how I can google whale skeletons and find nothing except on one species. Little 'L' bones about the size of your fingers in the vicinity of the anus. It requires quite a story to remove a hipbone and complete leg. Especially when the mammals that whales evolved from needed their legs to swim. They must have grown all their working fins first, before their legs evolved into little bones sorry--couldn't resist!

Hey would n't they have had to had some deformed legs or something, after their fins developed. Yeah it alwys worked out fine--because after all its here!

I've heard contradictions from evos also. First, there is the implication that vestigial organs are useless leftovers of evolution, but yet when natural selection is brought up and the why of it still being there, well there are still purposes for the organs.

In some cases vestiges take on new roles, but that would be the result of a selective pressure. Penguins have vestigial wings which are useless for flight but act as excellent swimming flippers. ThereÃ¢â‚¬â„¢s no contradiction in this. The wings are still vestigial if you define wings as being used for flight.

We now know the appendix is useful in that it fights harmful bacteria in our intestines. Now it will surely be spun that "see, it is still there because it was selected for." This only shows macro evolution is in your head. How do you know it wasn't created that way?

The appendix may have a purpose, but does it influence survival? I know several people who had their appendix taken out, and they donÃ¢â‚¬â„¢t seem to have any intestinal problems whatsoever. Thanks to modern medicine, the appendix is no longer affected by natural selection, at least not to a significant extent. So I donÃ¢â‚¬â„¢t think the appendix is still around because itÃ¢â‚¬â„¢s useful and necessary. ItÃ¢â‚¬â„¢s still around because thereÃ¢â‚¬â„¢s very little selective force acting against it, from either direction.

Especially when the mammals that whales evolved from needed their legs to swim. They must have grown all their working fins first, before their legs evolved into little bones sorry--couldn't resist!

Whales swim using undulations of their spine (up and down, as opposed to the lateral undulations of fish and reptiles). Fins arenÃ¢â‚¬â„¢t used for propulsion.

In some cases vestiges take on new roles, but that would be the result of a selective pressure. Penguins have vestigial wings which are useless for flight but act as excellent swimming flippers. ThereÃ¢â‚¬â„¢s no contradiction in this. The wings are still vestigial if you define wings as being used for flight.

Wait I'm confused. What is the A premise--that they are leftovers, and heirlooms, so they're useless right? Or just partly useful, but mostly useful . But mostly useless? The appendix is useful but not that useful, so it's vestigial. Sounds like a semantic shell game.

The appendix may have a purpose, but does it influence survival? I know several people who had their appendix taken out, and they donÃ¢â‚¬â„¢t seem to have any intestinal problems whatsoever. Thanks to modern medicine, the appendix is no longer affected by natural selection, at least not to a significant extent. So I donÃ¢â‚¬â„¢t think the appendix is still around because itÃ¢â‚¬â„¢s useful and necessary. ItÃ¢â‚¬â„¢s still around because thereÃ¢â‚¬â„¢s very little selective force acting against it, from either direction.Ã‚Â

I know a deaf person, and he is still alive. So is the ear vestigial? Isn't the truth that they thought at one time the appendix was useless, and now they know that's not true. The premise is deleted, but you still use it to form a postulate.

Whales swim using undulations of their spine (up and down, as opposed to the lateral undulations of fish and reptiles). Fins arenÃ¢â‚¬â„¢t used for propulsion.

I didn't know I made a statement about propulsion. My pondering was the 'pathway' of evolution.

The crocodile like ambulocetus jumped in with legs and a tail that would have moved laterally instead of up and down movements. So did the legs disappear first, or hang limply deformed as it evolved, or did they get smaller gradually? Why would they get smaller and smaller if they needed them to survive.? The large legged ones would have been selected.

Did the tail go diagonal for a while and then up and down (you know, step by step), or did it just get mutated to go up and down in one big step.

Wait I'm confused. What is the A premise--that they are leftovers, and heirlooms, so they're useless right? Or just partly useful, but mostly useful. But mostly useless? The appendix is useful but not that useful, so it's vestigial. Sounds like a semantic shell game.

I like WikipediaÃ¢â‚¬â„¢s definition of vestigial:

"Vestigiality describes homologous characters of organisms that have seemingly lost all or most of their original function in a species through evolution. These may take various forms such as anatomical structures, behaviors and biochemical pathways."

Vestigial means that the original function has been lost. So the appendix may provide some benefits to the intestinal tract, but it no longer performs its original role of cellulose digestion.

I know a deaf person, so is the ear vestigial.

If deaf people were a separate species that consistently gave birth to deaf offspring, then yes the ear would be considered vestigial. But this isnÃ¢â‚¬â„¢t the case.

The crocodile like ambulocetus jumped in with legs and a tail that would have moved laterally instead of up and down movements.

Did the tail go diagonal for a while and then up and down (you know, step by step), or did it just get mutated to go up and down in one big step.

Why would it have moved laterally? Whales evolved from mammals, and all mammals (including humans) swim with vertical undulations. Ambulocetus looked a bit like a crocodile, but it was a mammal.

So did the legs disappear first, or hang limply deformed as it evolved, or did they get smaller gradually? Why would they get smaller and smaller if they needed them to survive.? The large legged ones would have been selected.

They probably got smaller gradually. Why would they be needed for survival? Extra limbs on an aquatic animal are a hindrance unless theyÃ¢â‚¬â„¢re involved in locomotion. They increase drag and make the body less streamlined.

That requires one to assume evolution int he first place to believe. Why couldn't it have been created that way?

CouldÃ¢â‚¬â„¢ve been, but since itÃ¢â‚¬â„¢s not necessary for survival and can actually cause death without medical attention I find it a lot more likely that it evolved. Also the fact that it resembles a reduced version of the functional caeca found in herbivores seems to support the evolution theory.

Non-Marine mammals, as far I remember, use their limbs to swim and not their bodies.

When you say non-marine, do you mean freshwater mammals like river otters? Because they swim with vertical undulations too. My point is just that if itÃ¢â‚¬â„¢s a mammal, itÃ¢â‚¬â„¢s going to undulate vertically and not laterally. The extent to which these undulations are used for propulsion depends on the animal. Often the limbs provide the primary force, like the webbed feet of a beaver.

CouldÃ¢â‚¬â„¢ve been, but since itÃ¢â‚¬â„¢s not necessary for survival and can actually cause death without medical attention I find it a lot more likely that it evolved. Also the fact that it resembles a reduced version of the functional caeca found in herbivores seems to support the evolution theory.

It is helpful to survival, it's just that today's medicine does it's purpose as well. You might as well say certain joints are not useful because versions made of metal can be made and used instead.

It is helpful to survival, it's just that today's medicine does it's purpose as well.

The appendix may have some benefits, but it doesnÃ¢â‚¬â„¢t help with survival. A ruptured appendix can result in death. Has anyone died from having their appendix successfully removed? My dad had his appendix taken out when he was 9, and heÃ¢â‚¬â„¢s never had any sort of intestinal problems.

They probably got smaller gradually. Why would they be needed for survival? Extra limbs on an aquatic animal are a hindrance unless theyÃ¢â‚¬â„¢re involved in locomotion. They increase drag and make the body less streamlined.

Your starting to see the concept I'm putting forth ! They would have been a hindrance only after the tail and fins were functional, but on the other hand while the tail and fins were forming, they would have been a hindrance to the transition animals. So selection works against this change.

Dorudon was a species of whale with little tiny bones they wish was a pelvis. Probably supported fins.

Wiki--Gaviacetus was a primitive cetacean that lived approximately 45 million years ago. Although often represented as having small hind limbs,[2] this is an inference from the general progression of other fossil species towards limb loss; the only postcranial remains found for Gaviacetus itself were a rib and two vertebrae.[1]

Wiki--Takracetus was a primitive cetacean that lived approximately 45 million years ago. The type specimen (GSP-UM 3041) was a partial skull[1] though the literature mentions a second more complete skeleton.[2]

Here's Rodhocetus

So the fossil record gives us two four legged mammals, with small tails. Two skulls and an extinct whale, and wants to believe selection magically removed the needed legs while it formed a tail, fins, an d all other kinds of anatomical features. An incredible leap that is called evidence.

No model is given, to show us how selection did this--remove legs, and evolve all the needed whale phenotype. Legs would be needed until the tail and fins formed. You are stuck with both legs, fins and a tail.

Don't blame creationists when they say "half tails." If the concept is wrong then give us a step by step model.

Now what do you guys think about this ? Dont know if its been posted before im new

Don't you have an actual unbiased scientific research link as opposed to this religious philosophical worldview site ?

It makes the discussion so much more interesting and educational.

The terminology "Vestigial Organs" did at one time actually have it's own vestigial purpose as an atheist/evolutionist propaganda tool. But this has long since lost it's value as a pseudo-science propaganda tool in the light of modern day real unbiased scientific research. How many times in numerous forums do we hear an Atheist accuse someone who believes in creation of taking the lazy way out, failing to explain something by giving up and saying, Ã¢â‚¬Å“God did it.Ã¢â‚¬Â But in the sorry history of vestigial organ theory, it seems the shoe all too often on the other foot as well. Instead of finding the important function of an unknown organ, evolutionists have tendancy to give up and say, Ã¢â‚¬Å“ItÃ¢â‚¬â„¢s just an evolutionary leftover.Ã¢â‚¬Â Hence the numerous lame and lazy responses above.

Your starting to see the concept I'm putting forth ! They would have been a hindrance only after the tail and fins were functional, but on the other hand while the tail and fins were forming, they would have been a hindrance to the transition animals. So selection works against this change.Dorudon was a species of whale with little tiny bones they wish was a pelvis. Probably supported fins.

Wiki--Gaviacetus was a primitive cetacean that lived approximately 45 million years ago. Although often represented as having small hind limbs,[2] this is an inference from the general progression of other fossil species towards limb loss; the only postcranial remains found for Gaviacetus itself were a rib and two vertebrae.[1]

Wiki--Takracetus was a primitive cetacean that lived approximately 45 million years ago. The type specimen (GSP-UM 3041) was a partial skull[1] though the literature mentions a second more complete skeleton.[2]

Here's Rodhocetus

So the fossil record gives us two four legged mammals, with small tails. Two skulls and an extinct whale, and wants to believe selection magically removed the needed legs while it formed a tail, fins, an d all other kinds of anatomical features. An incredible leap that is called evidence.

No model is given, to show us how selection did this--remove legs, and evolve all the needed whale phenotype. Legs would be needed until the tail and fins formed. You are stuck with both legs, fins and a tail.

Don't blame creationists when they say "half tails." If the concept is wrong then give us a step by step model.

This is one of the greatest religious myths which is every equal the rival of anything from ancient Greece or Rome. I'm surprised they haven't included a fossil of Hercules battling this thing in the Cambrian layer with his father Zeus' guidence.

Don't you have an actual unbiased scientific research link as opposed to this religious philosophical worldview site ?

It makes the discussion so much more interesting and educational. The terminology "Vestigial Organs" did at one time actually have it's own vestigial purpose as an atheist/evolutionist propaganda tool. But this has long since lost it's value as a pseudo-science propaganda tool in the light of modern day real unbiased scientific research. How many times in numerous forums do we hear an Atheist accuse someone who believes in creation of taking the lazy way out, failing to explain something by giving up and saying, Ã¢â‚¬Å“God did it.Ã¢â‚¬Â But in the sorry history of vestigial organ theory, it seems the shoe all too often on the other foot as well. Instead of finding the important function of an unknown organ, evolutionists have tendancy to give up and say, Ã¢â‚¬Å“ItÃ¢â‚¬â„¢s just an evolutionary leftover.Ã¢â‚¬Â Hence the numerous lame and lazy responses above.

What the article fails to tell us is that about 1 in 100,000 people are born without an appendix and they exhibit normal bacteria and gut flora levels. This coupled with the removal of the appendix during serious infection clearly shows that the appendix may have served a purpose in our past and may serve some little purpose now but will not and does not affect our lifestyles after it is removed or if it is non-existent from birth. I've pointed this out in other threads on here.

Don't you have an actual unbiased scientific research link as opposed to this religious philosophical worldview site ?

It makes the discussion so much more interesting and educational. The terminology "Vestigial Organs" did at one time actually have it's own vestigial purpose as an atheist/evolutionist propaganda tool. But this has long since lost it's value as a pseudo-science propaganda tool in the light of modern day real unbiased scientific research. How many times in numerous forums do we hear an Atheist accuse someone who believes in creation of taking the lazy way out, failing to explain something by giving up and saying, “God did it.” But in the sorry history of vestigial organ theory, it seems the shoe all too often on the other foot as well. Instead of finding the important function of an unknown organ, evolutionists have tendancy to give up and say, “It’s just an evolutionary leftover.” Hence the numerous lame and lazy responses above.